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Related papers: Fast fitting of spectral lines with Gaussian and h…

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HfS is a tool to fit the hyperfine structure of spectral lines, with multiple velocity components. The HfS_nh3 procedures included in HfS fit simultaneously the hyperfine structure of the NH$_3$ (J,K)= (1,1) and (2,2) transitions, and…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 Robert Estalella

Next-generation solar spectrographs increasingly record dense wavelength windows in which tens to hundreds of spectral lines are sampled at each spatial location and time step. This expands the scope for multi-line, multi-height diagnostics…

Integral field spectroscopy (IFS) provides spatially resolved spectra, enabling detailed studies that address the physical and kinematic properties of the interstellar medium. A critical step in analyzing IFS data is the decomposition of…

Astrophysics of Galaxies · Physics 2026-02-10 Hui Guo , Guilin Liu , Jianghui Xu , Chao Geng , Zhicheng He , Shiyin Shen , Lei Hao

Spectral lines from interstellar molecules provide crucial insights into the physical and chemical conditions of the interstellar medium. Traditional spectral line analysis relies heavily on manual intervention, which becomes impractical…

Astrophysics of Galaxies · Physics 2026-01-14 Yisheng Qiu , Tianwei Zhang , Tie Liu , Fengyao Zhu , Dezhao Meng , Huaxi Chen , Thomas Möller , Peter Schilke , Donghui Quan

The specification of a covariance function is of paramount importance when employing Gaussian process models, but the requirement of positive definiteness severely limits those used in practice. Designing flexible stationary covariance…

Computation · Statistics 2024-05-01 Paul G. Beckman , Christopher J. Geoga

Gaussian processes (GPs) are generally regarded as the gold standard surrogate model for emulating computationally expensive computer-based simulators. However, the problem of training GPs as accurately as possible with a minimum number of…

Methodology · Statistics 2024-11-26 Hossein Mohammadi , Peter Challenor

Modelling complex line emission in the interstellar medium (ISM) is a degenerate, high-dimensional problem. Here, we present McFine, a tool for automated multi-component fitting of emission lines with complex hyperfine structure, in a fully…

Astrophysics of Galaxies · Physics 2024-09-11 Thomas G. Williams , Elizabeth J. Watkins

Given a graphical model (GM), computing its partition function is the most essential inference task, but it is computationally intractable in general. To address the issue, iterative approximation algorithms exploring certain local…

Machine Learning · Computer Science 2019-05-15 Sejun Park , Eunho Yang , Se-Young Yun , Jinwoo Shin

In all applications of gamma-ray spectroscopy, one of the most important and delicate parts of the data analysis is the fitting of the gamma-ray spectra, where information as the number of counts, the position of the centroid and the width,…

Instrumentation and Detectors · Physics 2015-11-16 Guilherme S. Zahn , Frederico A. Genezini , Maurício Moralles

We provide a detailed description of the Herschel-SPIRE Fourier Transform Spectrometer (FTS) Spectral Feature Finder (FF). The FF is an automated process designed to extract significant spectral features from SPIRE FTS data products.…

Instrumentation and Methods for Astrophysics · Physics 2020-06-24 R. Hopwood , I. Valtchanov , Locke D. Spencer , J. P. Scott , C. S. Benson , N. Marchili , N. Hladczuk , E. T. Polehampton , N. Lu , G. Makiwa , D. A. Naylor , B. G. Gom , G. Noble , M. J. Griffin

Structural parameters are normally extracted from observed galaxies by fitting analytic light profiles to the observations. Obtaining accurate fits to high-resolution images is a computationally expensive task, requiring many model…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 Benjamin R. Barsdell , David G. Barnes , Christopher J. Fluke

X-ray spectral fitting in high-energy astrophysics can be reliably accelerated using Machine Learning. In particular, Simulation-based Inference (SBI) produces accurate posterior distributions in the Gaussian and Poisson regime for…

Instrumentation and Methods for Astrophysics · Physics 2025-07-09 Simon Dupourqué , Didier Barret

Identifying the underlying models in a set of data points contaminated by noise and outliers, leads to a highly complex multi-model fitting problem. This problem can be posed as a clustering problem by the projection of higher order…

Computer Vision and Pattern Recognition · Computer Science 2018-08-01 Ruwan Tennakoon , Alireza Sadri , Reza Hoseinnezhad , Alireza Bab-Hadiashar

In this paper we describe the FIT\textit{spec} code, a data mining tool for the automatic fitting of synthetic stellar spectra. The program uses a database of 27\,000 {\sc cmfgen} models of stellar atmospheres arranged in a six-dimensional…

We rederive from first principles and generalize the theoretical framework of the nonlinear Gaussian noise model to the case of coherent optical systems with multiple fiber types per span and ideal Nyquist spectra. We focus on the accurate…

Signal Processing · Electrical Eng. & Systems 2020-09-15 I. Roudas , J. Kwapisz , X. Jiang

Radiative transfer effects need to be taken into account when analysing spectral line observations. When the data are not sufficient for detailed modelling, simpler methods are needed. The escape probability formalism (EPF) is one such…

Instrumentation and Methods for Astrophysics · Physics 2025-04-16 Mika Juvela

This paper introduces a general method to approximate the convolution of an arbitrary program with a Gaussian kernel. This process has the effect of smoothing out a program. Our compiler framework models intermediate values in the program…

Graphics · Computer Science 2017-06-06 Yuting Yang , Connelly Barnes

Many computer vision and human-computer interaction applications developed in recent years need evaluating complex and continuous mathematical functions as an essential step toward proper operation. However, rigorous evaluation of this kind…

Optimization and Control · Mathematics 2017-11-10 Daniel Berjón , Guillermo Gallego , Carlos Cuevas , Francisco Morán , Narciso García

Fitting a theoretical model to experimental data in a Bayesian manner using Markov chain Monte Carlo typically requires one to evaluate the model thousands (or millions) of times. When the model is a slow-to-compute physics simulation,…

Machine Learning · Statistics 2022-08-25 Steven Stetzler , Michael Grosskopf , Earl Lawrence

I start by providing an updated summary of the penalized pixel-fitting (pPXF) method, which is used to extract the stellar and gas kinematics, as well as the stellar population of galaxies, via full spectrum fitting. I then focus on the…

Astrophysics of Galaxies · Physics 2017-01-11 Michele Cappellari
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